Various types of board structures are known for interior automotive trims, such as, for example, a deck board disposed on a floor of a trunk space in which a recessed storage portion for storing spare tires is formed and a parcel shelf for dividing trunk space into an upper space and a lower space, in the interior space of an automobile. For these types of board structures, a predetermined load bearing capability is required, and also, weight reduction is becoming increasingly important from the perspective of the handleability of the board structures and fuel consumption reduction of the vehicles.
For such lightweight boards, there are known boards in which a honeycomb structure is used as a base material, the honeycomb structure including a plurality of small individual chambers (cells) therein, the boards having reduced weight and enhanced rigidity by charging and foaming a foamable thermosetting resin in the cells of the honeycomb structure.
For example, Patent Literature 1 discloses a board structure for the interior automotive trim, the board structure being formed by putting a glass fiber mat impregnated with a foamable thermosetting resin on each of opposite sides of a honeycomb structure, and subjecting the resulting honeycomb structure with the glass fiber mats thereon to heat molding, thereby foaming and charging the thermosetting resin in the cells of the honeycomb structure. In addition, Patent Literature 2 discloses a floor covering member for the trunk space of an automobile, the floor covering member including integral hinges formed by thermofusion of a honeycomb layer.
A deck board disposed on a floor of a trunk space in an automobile is intended to enable opening/closing an opening of a recessed storage portion, and to provide a flat floor surface of the trunk space. Since such deck board is formed so as to cover substantially the entire floor surface of the trunk space, it is necessary to open/close the deck board in its entirety in order to access the recessed storage portion. Accordingly, when opening/closing the deck board in its entirety, it is necessary to temporarily take goods loaded on the deck board to the outside of the vehicle, and thus, such deck board is poor in handleability and convenience. Therefore, in order to enhance the convenience of deck boards, a configuration in which a deck board is divided by forming a hinge so that a part of the deck board can pivot with reference to the hinge as a pivot axis, thus enabling opening/closing of only a part of an opening of a recessed storage portion, is employed.